Effects of Varying Levels of Liquid DL-Methionine Hydroxy Analog Free Acid in Drinking Water on Production Performance and Gastrointestinal Tract of Broiler Chickens at 42 Days of Age

This study was conducted to evaluate the effects of adding liquid DL-methionine hydroxyl analog free acid (LMA) to drinking water on the growth performance and gastrointestinal tract in broiler chicks during 1-42 days of age. The chicks were divided into 5 groups as follows, Group 1 (negative control); chicks received a methionine (Met) deficient diet without LMA supplementation in drinking water. Group 2, 3, 4 and 5 were diets supplemented with DL-methionine (DLM) that meet total sulfur amino acids (TSAA) requirement, then each group was graded level with LMA in drinking water at 0%, 0.025%, 0.05% and 0.1%, respectively. Average daily gain (ADG) and feed conversion ratio (FCR) were significantly improved by DLM supplementation in diet. Furthermore, adding LMA at 0.025% and 0.050% to drinking water showed better growth performance than that of DLM supplementation group (p<0.01). Met deficient significantly induce low consumption of feed and water (p<0.05). The pH of drinking water was significantly reduced by LMA supplementation (p<0.001), consequently water consumption of 0.1% LMA in drinking water group was significantly lower than that of the Met sufficient diet group (0.0% LMA). However, the acidity of drinking water did not affect to acid-base value in the gastrointestinal tract, and population of E. coli or Lactohasillus spp in the ceacum. Adding LMA 0.05% in drinking water significantly increased villous height, villous surface area and crypth depth in the duodenum and jejunum (p<0.01). Concentration of propionic acid and total volatile fatty acid (total VFAs) were increased (p<0.001). The result indicate that adding LMA in drinking water 0.05% can be used as Met source and an acidifier to achieve maximal growth performance of broiler chicks via the improvement of gut morphology.